I don't think it would require much work to bump this engine up to 850 hp but the owner didn't seem interested. The engine goes in a pickup that he drag races and he runs low 9's or high 8's and is happy with it.
From what I've seen over the years only about 5% of the customers are actually interested in finding more power after a dyno session. Most customers just want to get the engine home so they can put it in the car and get back to racing.